<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>相册预览</title>
    <style>
        body{
            font-family: Verdana, sans-serif;
            margin: 0;
        }
        *{
            box-sizing: border-box;
        }
        .row>.column{
            padding: 0 8px;
        }
        /*.row:after{
            content: '';
            display: table;
            clear: both;
        }*/
        .column{
            float: left;
            width: 25%;
        }
        /*弹窗背景*/
        .modal{
            display: none;
            position: fixed;
            z-index: 1;
            padding-top: 100px;
            left:0;
            top:0;
            width: 100%;
            height: 100%;
            overflow: auto;
            background-color: black;
        }
        /*弹窗内容*/
        .modal-content{
            position: relative;
            background-color: #fefefe;
            margin: auto;
            padding: 0;
            width: 90%;
            max-width: 1200px;
        }
        /*关闭按钮*/
        .close{
            color: white;
            position: absolute;
            top: 10px;
            right: 25px;
            font-size: 35px;
            font-weight: bold;
        }
        .close:hover,
        .close:focus{
            color: #999;
            cursor: pointer;
        }
        .cursor{
            cursor: pointer;
        }
        /*上一页，下一页按钮*/
        .prev,
        .next{
            cursor: pointer;
            position: absolute;
            top: 50%;
            width: auto;
            padding: 16px;
            margin-top: -50px;
            color: white;
            font-weight: bold;
            font-size: 20px;
            transition: 0.6s ease;
            border-radius: 0 3px 3px 0;
        }
        .next{
            right:0;
            border-radius: 3px 0 0 3px;
        }
        /*鼠标移动上去修改背景颜色为黑色*/
        .prev:hover,
        .next:hover{
            background-color: rgba(0,0,0,0.8);
        }
        /*页数*/
        .numbertext{
            color: #f2f2f2;
            font-size: 12px;
            padding: 8px 12px;
            position: absolute;
            top: 0;
        }
        img{
            margin-bottom: -4px;
        }
        .caption-container{
            text-align: center;
            background-color: black;
            padding: 2px 16px;
            color: white;
        }
        .demo{
            opacity: 0.6;
        }
        .active,
        .demo:hover{
            opacity: 1;
        }
        img.hover-shadow{
            transition: 0.3s;
        }
        .hover-shadow:hover{
            box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2),0 6px 20px 0 rgba(0,0,0,0.19)
        }
        .mySlides{
            display: none;
        }
    </style>
</head>
<body>
<h2 style="text-align: center;">Lightbox</h2>
<div class="row">
    <div class="column">
        <img src="imgs/4.jpg" style="width: 100%;" onclick="openModal();currentSlide(0)" class="hover-shadow cursor"/>
    </div>
    <div class="column">
        <img src="imgs/5.jpg" style="width: 100%;" onclick="openModal();currentSlide(1)" class="hover-shadow cursor"/>
    </div>
    <div class="column">
        <img src="imgs/6.jpg" style="width: 100%;" onclick="openModal();currentSlide(2)" class="hover-shadow cursor"/>
    </div>
    <div class="column">
        <img src="imgs/7.jpg" style="width: 100%;" onclick="openModal();currentSlide(3)" class="hover-shadow cursor"/>
    </div>
</div>
<div id="myModal" class="modal">
    <span class="close cursor" onclick="closeModal()">&times</span>
    <div class="modal-content">
        <div class="mySlides">
            <div class="numbertext">1 / 4</div>
            <img src="imgs/4.jpg" style="width: 100%;"/>
        </div>
        <div class="mySlides">
            <div class="numbertext">2 / 4</div>
            <img src="imgs/5.jpg" style="width: 100%;"/>
        </div>
        <div class="mySlides">
            <div class="numbertext">3 / 4</div>
            <img src="imgs/6.jpg" style="width: 100%;"/>
        </div>
        <div class="mySlides">
            <div class="numbertext">4 / 4</div>
            <img src="imgs/7.jpg" style="width: 100%;"/>
        </div>
        <a class="prev" onclick="plusSlides(-1)">&#10094;</a>
        <a class="next" onclick="plusSlides(1)">&#10095;</a>
        <div class="caption-container">
            <p id="caption"></p>
        </div>
        <div class="column">
            <img class="demo cursor" src="imgs/4.jpg" style="width: 100%;" onclick="currentSlide(0)" alt="Nature and sunrise"/>
        </div>
        <div class="column">
            <img class="demo cursor" src="imgs/5.jpg" style="width: 100%;" onclick="currentSlide(1)" alt="Trolltunga, Norway"/>
        </div>
        <div class="column">
            <img class="demo cursor" src="imgs/6.jpg" style="width: 100%;" onclick="currentSlide(2)" alt="Mountains and fjords"/>
        </div>
        <div class="column">
            <img class="demo cursor" src="imgs/7.jpg" style="width: 100%;" onclick="currentSlide(3)" alt="Northern Lights"/>
        </div>
    </div>
</div>
<script>
    var slideIndex = 0;
    function openModal () {
        document.getElementById('myModal').style.display = 'block';
    }
    function closeModal () {
        document.getElementById('myModal').style.display = 'none';
    }
    function currentSlide (n) {
        showSlides(slideIndex = n)
    }
    function plusSlides (n) {
        showSlides(slideIndex += n)
    }
    function showSlides (n) {
        var i;
        var slides = document.getElementsByClassName('mySlides');
        var dots = document.getElementsByClassName('demo');
        for(i = 0; i < slides.length; i++){
            slides[i].style.display = 'none';
        }
        for(i = 0; i< dots.length; i++){
            dots[i].className = dots[i].className.replace(' active','');
        }
        if(n >= slides.length){slideIndex = 0}
        if(n < 0){slideIndex = slides.length-1}
        slides[slideIndex].style.display = 'block';
        dots[slideIndex].className += ' active';
    }
</script>
</body>
</html>